1 boiler hp	= 34.5 pounds per hr	1 boiler hp	= 33,479 btu per hr
boiler hp	= btu per hr / 33,479	btu per hr	= boiler hp X 33,479
boiler hp	= pounds per hr / 34.5	pph	= boiler hp X 34.5
natural gas	= 1000 btu per cubic ft	#2 oil	= 140,000 btu per gal
#4 oil	= 142 to 146,000 btu per gal	#6 oil	= 148 to 154,000 btu per gal
1 psi	= 2.31 ft of head	1 gal (water)	= 8.33 lbs
1 gal	= 231 cubic in	1 cubic ft	= 7.48 gal
1 cubic ft	= 1728 cubic in	gal	= cubic ft X 7.48052
cubic ft	= gal X 0.1337	dia	= radius X 2
circum	= dia X 3.1416	area of circle	= dia X dia X 0.7854
vol of cyl	= length X area	vol of rect	= length X width X height
cap. in gal	= volume in cubic inches / 231	cap. in gal	= volume in cubic feet X 7.48
1 gal	= 0.2642 liters	1 liter	= 3.78533 gal
1 in	= 2.5400 cm	1 cm	= 0.3937 in